<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<h1>个人信息：</h1>
		<script>
			// js 的代码是 读一句 执行一句
			var a = 123;
			
			console.log(a) // 123
			
			a = 456;
			console.log(a) //456
			
			var b = a;
			console.log(a) //456
			
		</script>
	</body>
</html>
